The present invention relates to a combination of a waistrest and a backrest and, more particularly, to a backrest allowing easy assembly and easy adjustment/positioning of a waistrest.
A waistrest is provided on a chair to support the waist of a user for avoiding discomfort of the waist due to long-term sitting. The waistrest is generally fixed to a backrest of the chair and is, thus, not suitable for various users of various body sizes such that the waist of the user may not be well supported.
In an approach, a movable waistrest is mounted to the backrest by an adjustment knob through threading coupling. The adjustment knob can be loosened by a tool to allow adjustment of the position of the waistrest relative to the backrest and then tightened again by the tool through threading coupling. However, the adjustment is inconvenient to the user, as the tool is required to loosen/tighten the adjustment knob, and positioning of the waistrest is risky if the adjustment knob is not tightened.